In line with R. Isaac’s expository method, it is possible to suggest yet another triad of terms corresponding to the conceptual model of “the three Kabbalot.” This triad is taken as well from the Tanya, specifically from the segment entitledSha’ar Hayichud V’haEmunah (“The Gate of Unity and Faith”). There, Rabbi Shneur Zalman of Liadi describes the process whereby God forms and sustains all of Creation through an infinite number of Hebrew letter permutations, each of which conveys three levels of Divine lifeforce: koach, chayut, and ohr.
Koach represents the innate “power” or “energy” which condenses into the very substance of Creation itself, be it in physical or spiritual form. This is comparable to the energy which Einstein identified as the ultimate component of all matter. The equivalence between energy and matter is expressed in the Kabbalah by the statement: mehitabut ha’orot, nithavu hakelim–“from the condensation of the lights, were the vessels brought into being.” This concept relates to the system of the Ramak, which sets out to delineate the evolving forms of energy (the sefirot) underlying the very substance of Creation.
Chayut represents the inner “lifeforce,” or soul, which fills the substance of Creation with an independent consciousness of the Divinity immanent within it. There is a quantum distinction between innate “energy,” inhering within the actual forms of Creation, and “lifeforce,” which while mysteriously enclothing itself within reality remains attached to its Divine source. Hence chayut corresponds to the system of the Ari which, as we have seen, deals directly with the process of hitlavhsut (“enclothement”) and the possibility of souls transmigrating from “vessel” to “vessel” within Creation.
Ohr represents the all-encompassing infinite “light” which inspires every element within Creation to transcend the boundaries of its own nature and become absolutely one with God. According to the Ba’al Shem Tov, the infinite light of God, which by definition disallows any other form of existence, paradoxically remains within the “empty space” which God cleared as a “womb” for His unfolding Creation. The Ari‘s description of the withdrawal, or disappearance, of this infinite light is understood in Chassidic thought as emanating from the perspective of Creation itself, whose finite consciousness cannot accommodate the truth of God’s essential immutability. According to the Ba’al Shem Tov, the closer we come to the Messianic age, the more attuned we become to God’s omnipresence within Creation; hence the centrality of hashra’ah within his system of thought.
More information about Kabblah you can read in “What you need to know about Kabbalah”